The present invention relates to apparatuses and methods for computing tissue glucose non-invasively
Diabetes is a global health burden, declared by World Health Organization (WHO) as a global epidemic due to its rapidly growing prevalence. It is a chronic disease in which sugar levels are increased in the body due to either insufficient insulin production by the pancreas or un-effective usage of insulin by the body. The effects of diabetes include long-term damage, dysfunction and failure of various organs including the retina, kidney and vasculature.
Intensive management of blood glucose levels is crucial in diabetes management and treatment. The Diabetes Control and Complications Trial and the UK Prospective Diabetes Study follow-up showed that early, tight glucose control in people with Type 1 and Type 2 diabetes reduced the risk of development or progression of long-term diabetes complications.
Today, finger stick testing is the mainstay of blood glucose detection. Sufficient blood glucose monitoring requires frequent (more than four times a day) blood measurements accompanied by discomfort and pain.
The need for convenient blood glucose self-monitoring technique has led to the development of alternative technologies including the continuous and non-invasive monitoring. Continuous blood glucose devices require invasive sensor inserted under the skin, being replaced at least once or twice a month, which is inconvenient and expensive.
So far, several non-invasive methods including near-infrared spectroscopy, Raman spectroscopy, ultrasound and so forth were proposed, however no satisfactory solution was introduced to the market. Optical methods have failed to recognize blood glucose levels mainly because glucose has weak connection to light, e.g. visual to IR light. Moreover, it is highly unlikely to calibrate the entire worldwide population under universal calibration manifold with so many obstacles on the way, such as: tissue perfusion, tissue temperature, other blood substance, hemodynamic factors, skin color, nails, dry skin, etc. Furthermore, glucose is less than 0.1% of human tissue by weight. Therefore, variances due to thermal, mechanical, hemodynamics, optical, or other instabilities may interfere with the non-invasive glucose reading.